U.S. patent number 5,044,978 [Application Number 07/530,055] was granted by the patent office on 1991-09-03 for cable connector block, in particular for a screened pair.
This patent grant is currently assigned to Cegelec. Invention is credited to Claude Gelin.
United States Patent |
5,044,978 |
Gelin |
September 3, 1991 |
Cable connector block, in particular for a screened pair
Abstract
A connector block enables an electrical device to be put into
series with a cable having two wires, a drain and a metal sheath
covered with an insulating covering. The insulating covering and
the metal sheath are removed from a length L of the cable, and the
drain and the wires are put into place longitudinally on a support
provided with insulating piercing contact pieces for fixing and
connecting the wires to a take-off cable. A cutting device slides
in a housing in the support and cuts each wire between two contact
pieces.
Inventors: |
Gelin; Claude (Creteil,
FR) |
Assignee: |
Cegelec (Levallois Perret,
FR)
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Family
ID: |
9382219 |
Appl.
No.: |
07/530,055 |
Filed: |
May 29, 1990 |
Foreign Application Priority Data
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May 31, 1989 [FR] |
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89 07182 |
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Current U.S.
Class: |
439/394;
439/579 |
Current CPC
Class: |
H01R
9/0509 (20130101); H01R 4/2454 (20130101) |
Current International
Class: |
H01R
9/05 (20060101); H01R 4/24 (20060101); H01R
004/24 () |
Field of
Search: |
;439/579,582,578,394,395,402,403,607,609,610 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0251396 |
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Jan 1988 |
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EP |
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2509126 |
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Sep 1975 |
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DE |
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2936616 |
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Mar 1981 |
|
DE |
|
Primary Examiner: Pirlot; David L.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak &
Seas
Claims
I claim:
1. A connector block for a screened pair cable including a drain
wire and first and second insulated wires inside a metal sheath and
an outer insulating cover, said block comprising:
a support and a slidable cutting device;
said support including a housing slidably mounting the cutting
device for movement between a first extracted end position and a
second projected end position, and first and second sets of
insulation-piercing contact pieces, with the contact pieces in each
set being disposed on opposite sides of the housing with the first
and second insulated wires crossing the housing between the two end
positions of the slidable cutting device;
a length of said insulating covering and metal sheath being removed
at the location of the connector block, said first wire of the
cable being inserted in the contact pieces of the first set and the
second wire of the cable being inserted in the contact pieces of
the second set;
a similarly screened take-off cable being connected to an
electrical device and including four wires, each of said four wires
being connected to a respective one of the contact pieces in the
first and second sets of contact pieces; and
said slidable cutting device being pushed into the housing to said
second projected end position and said knives cutting the first and
second wires of the cable thereby putting said electrical device
into series with said cable.
2. A block according to claim 1, wherein the contact pieces of the
first and second sets of contact pieces are connected by straps
which re-establish continuity of the wires of the cable prior to
the series device being disconnected.
3. A connector block according to claim 1, wherein:
the support includes first, second, and third longitudinal
grooves;
the contact pieces being disposed in the first and second
groves;
the first and second wires being disposed in the first and second
grooves over the contact pieces and the drain wire being disposed
in the third groove;
a lid fixed on the support pressing the first and second wires in
the contact pieces;
the third groove is situated between the first and second
grooves;
the housing is constituted by first and second laterally spaced
compartments separated by the third groove, the first groove being
interrupted by the first compartment and the second groove being
interrupted by the second compartment;
said cutting device includes first and second branches received in
the first and second compartments respectively, passing through an
opening in the lid with each branch being U-shaped and having ends
defining knives which are perpendicular to the grooves;
whereby slidable depression of the cutting device applies pressure
to the cutting device; and
wherein the cutting device slidably projected to the second end
position applies pressure to the cutting device effecting severance
of a length of the first wire by the knives of said first branch
and severance of a length of a second wire by the knives of the
second branch.
4. A block according to claim 3, wherein each contact piece
includes at least one top branch disposed in a groove and at least
one bottom branch accessible from a bottom face of the support.
5. A connector block according to claim 3, wherein said block
further includes a bottom plate fixed to the support on a side
thereof opposite to the lid, and wherein each of the support, the
lid, and the bottom plate include metal coatings with all of the
metal coatings being electrically connected to the metal sheath of
the cable and to screening of the take-off cable to effect earthing
continuity and electromagnetic protection for the block.
6. A block according to claim 5, further comprising the two contact
pieces in the third groove connected to said metal coatings of said
support, said cover, and said bottom plate.
7. A block according to claim 3, wherein the third groove includes
two contact pieces into which the drain wire is inserted by said
lid.
8. A block according to claim 7, wherein each contact piece
includes at least one top branch disposed in a groove and at least
one bottom branch accessible from a bottom face of the support.
Description
The invention relates to connecting an electrical device to a cable
conveying a flow of information, the connection consisting in
putting the device in series with the cable which constitutes an
information bus.
BACKGROUND OF THE INVENTION
In a connection interconnecting a plurality of devices in a series,
the need often arises to add in an extra device in series, and this
is generally done by breaking the cable at the desired location and
by connecting the device to said cable. This way of proceeding
necessarily puts all of the devices out of operation while the
connection is being performed.
Such series links are commonly used in local networks for bus
transmission, the bus generally being a cable constituted a pair
which is screened to provide protection against external electrical
interference.
The object of the invention is to connect a device to a bus so as
to put the device in series with the said bus at any position along
the bus without causing a major disturbance to the flow of
information along the bus, i.e. without putting the link out of
service.
SUMMARY OF THE INVENTION
The present invention provides a connector block for a cable, in
particular a screened pair cable including a drain and first and
second insulated wires inside a metal sheath and an outer
insulating covering, wherein:
the block comprises a support and a cutting device;
said support includes a housing for the cutting device, and first
and second sets of insulation-piercing contact pieces, with the
contact pieces in each set being disposed on either side of the
housing;
the said insulating covering and metal sheath are removed from the
location where the connector block is to be disposed, the first
wire of the cable is inserted in the contact pieces of the first
set and the second wire of the cable is inserted in the contact
pieces of the second set;
a similarly screened take-off cable connected to an electrical
device includes four wires each connected to one of the contact
pieces in the first and second sets of contact pieces; and
the cutting device is pushed into the housing in order to cut the
first and second wires of the cable and to put the said electrical
device into series with the said cable.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is described by way of example with
reference to the accompanying drawings, in which:
FIG. 1 is a theoretical diagram of a connector block of the
invention;
FIG. 2 is a diagrammatic plan view of a connector block of the
invention;
FIG. 3 is a partially cut-away elevation view of a connector
block;
FIG. 4 shows a contact piece used in the connector block; and
FIG. 5 is a perspective view of a connector block.
DETAILED DESCRIPTION
FIG. 1 is a theoretical diagram of a connector block of the
invention. The cable 1 is a screened pair cable having an earthing
drain wire 4, with 2 and 3 designating the wires of the pair, 4 the
drain wire, and 5 a metal screening sheath covered with an
insulating covering 60. A cut-out of length L is formed at the
position where connection is to take place, with the outer
insulating covering 60 of the cable and its metal sheath 5 being
removed and with a short length L1 of covering 60 being removed on
either side of the cut-out so as to uncover metal sheath 5.
The cut-out gives access to the two wires 2 and 3 and to the drain
4 which is in metallic and electrical contact with the inside of
the metal sheath 5. Inside a support 50, the wire 2 is connected to
contact pieces 6 and 7, while the wire 3 is connected to contact
pieces 8 and 9. A screened take-off cable 20 having four wires 21,
22, 23, and 24 connects an electrical device 30 to the connector
block. The wires 21 to 24 are connected to respective ones of the
contact pieces 6 and 9. The contact pieces 6 and 9 are of the
insulation-piercing type, such that the wires 2 and 3 of the cable
1 are not cut. The device 30 is put into series with the wires 2
and 3 by cutting the wires 2 and 3 between contact pieces 6 and 7
or 8 and 9 as the case may be. This cutting is performed by means
of a cutting device 10 which slides in a housing at the moment the
device 30 is put into service.
Continuity of the screening of the cable 1 is provided by screening
11 interconnecting the ends 5a and 5b of the metal sheath 5 on
either side of the cut-out. Similarly, the ends 5a and 5b are
interconnected by screening 12 and 13 to the metal sheath 19 of the
cable 20 which is situated on a side exit of the support.
To ensure earthing continuity, the drain wire 4 is connected to the
screening 11 by contacts 35 and 36 placed on either side of the
cutting device 10, which device has no effect on said continuity
link.
Once the wires 2 and 3 have been cut with the device 30 then being
connected in series, it is possible to re-establish continuity of
said wires 2 and 3 by means of short-circuit straps 17 and 18
interconnecting contact pieces 6 and 7 or 8 and 9 as the case may
be. When the straps are in place the device 30 can be removed or
replaced.
FIG. 2 is a diagrammatic plan view and FIG. 3 is a partially
cut-away diagrammatic elevation view of a connector block of the
invention. In these figures, the same reference numerals have the
same meanings as in FIG. 1.
Two sets of gland packing 14 and 15 hold the cable 1 relative to
the support 50 and seal the connections between the cable and the
support. The wires 2 and 3 are disposed in grooves 25 and 27 in the
support with the drain 4 being disposed in a groove 26 in which it
is held by the contact pieces 35 and 36. The support 5 includes a
housing constituted by two compartments 28 and 29 in which
respective branches of the cutting device 10 slides. The
compartment 28 is situated between contact pieces 6 and 7 while the
compartment 29 is situated between contact pieces 8 and 9. These
compartments are situated on opposite sides of the groove 26, and
are thus separated from the said groove 26 in which the drain 4 is
disposed.
The connection block also includes an insulating lid 51 and an
insulating bottom plate 52 whose portions facing the support are
metal coated. The lid 51 and the support 50 are fixed together by
means of screws 40 which engage in holes 42 in the support, with
the bottom plate being fixed to the support 50 by screws 41.
The cutting device 10 which is shown in perspective in FIG. 5, is
made of insulating material. It has two branches 43 and 44 each of
which slides in a corresponding one of the compartments and each of
which is terminated by a U-shape portion whose ends 45 and 46
constitute two knives that slide along the walls of the
compartments that extend perpendicularly to the wires to be
cut.
When pushed home in a compartment, these two knives cut off a
portion 39 of wire extending between the two opposite walls of the
compartment.
In FIG. 3, the cutting device is shown in its down position, while
its up position is shown by dashed lines.
The contact pieces 6, 7, 8, and 9 may be constituted, for example,
by pairs of contact pieces as shown in FIG. 4. The contact pieces
35 and 36 for the drain wires are contact pieces of the type having
two opposite forks in conventional manner or else they are paired
contact pieces like the contact pieces 6, 7, 8, and 9 in order to
be electrically connected with the internal metallization of the
support, of the bottom plate, and of the lid, thereby ensuring
earthing continuity for the cable 1. The contact piece is in the
form of two U-shape portions sharing a common base 53.
A first U-shape portion comprises branches A and B, while the
second U-shape portion comprises branches C and D. The branches A
and B project to one side of the base 53 and the branches C and D
are situated on the other side of the said base, with the branches
A and B being at 90.degree. to the branches C and D. Each branch
includes an insulation-piercing slit F in conventional manner. A
contact piece serves to interconnect two insulated wires 3 and 23.
The wire 3 is inserted in the branches A and B so that its
conductor 54 makes contact with the edges of the slit F in these
branches. The wire 23 is inserted in the branches C and D so that
its conductor 55 makes contact with the edges of the slit F in
these branches. The wires 3 and 23 are perpendicular to each other.
The contact pieces 6, 7, 8, and 9 are all constituted by pairs of
contact pieces as shown in FIG. 4 and they therefore serve to
interconnect the cables 1 and 20 (FIG. 1) which cables are
perpendicular to each other.
FIG. 5 is a diagrammatic perspective view of a connector block
showing the cutting device 10 prior to being inserted in the block,
with the lid 51 including an opening 57 for this purpose. The
cutting device 10 includes two catches such as 56, one per branch
43, 44 of the cutting device. These catches are situated on
opposite sides of the cutting device and they engage with the lid
52 when in the down position in order to hold the cutting device in
said down position. The outlet from the block for the cable 20
takes place sideways with an insulating sleeve 58 holding and
sealing the end of the cable 20.
A connector block of the invention is installed as follows:
a cut-out is formed in the cable 1, at the desired location;
the wires 2 and 3 and the drain wire 4 are placed in the grooves
25, 26, and 27 of the support 50 over the contact pieces 6, 7, 8,
9, 35, and 36;
the sets of gland packing 14 and 15 are put into place and the lid
51 is screwed onto the support 50, and while the screws are being
tightened, the lid bears down on the wires 2 and 3 and on the drain
wire 4, thereby inserting them in the slits F of the contact
pieces; and
the cutting device 10 is inserted in the opening 57 of the lid 51
and is left in the high position, i.e. in a position where the
wires 2 and 3 are not cut.
The connection with the device 30 takes place with the bottom plate
removed. The wires 21, 22, 23 and 24 of the take-off cable 20 (FIG.
1) are inserted in the bottom branches of the contact pieces 6, 7,
8, and 9, and then the bottom plate is screwed onto the support,
such that while the screws of the bottom plate are being tightened,
the wires 21 to 24 are inserted into the slits of the bottom
branches of the contact pieces.
The cutting device 10 is then put home so that it occupies its down
position. The wires 2 and 3 are cut and the device 30 is connected
in series with the wires 2 and 3 of the cable 1.
It is also possible to begin by mounting the take-off cable 20 to
the connector block and then fix the block to the cable 1 in the
manner described above, with the device 20 being brought into
service, i.e. connected in series with the cable, by pushing home
the cutting device 10 after the lid 51 has been fixed to the
support 50. The metal coatings of the support, the lid, and the
bottom plate coming into contact with the metal sheaths of the
cable 1 and of the take-off cable 20 ensure that the connector
block has electromagnetic protection.
The up or down position of the cutting device 10 provides a visual
indication as to whether the branch connection is operational (i.e.
device 10 pushed home and locked in its down position) or not
operational (i.e. the device 10 projecting and locked in its up
position).
* * * * *